1. Technical Field
The present invention generally relates to wireless communication systems and in particular to scheduling information signals in wireless communication systems.
2. Description of the Related Art
Uplink (UL) Collaborative Spatial Division Multiple Access (SDMA) is one of the advanced features in mobile Worldwide Interoperability for Microwave Access (WiMAX), where two different single-antenna subscribers share the same Orthogonal Frequency Division Multiplexing (OFDM) time-frequency resources, transmitting independent data streams. Conventionally, any two users were randomly paired on a frame basis for the UL SDMA. This blind/random scheduling method simplifies implementation and reduces the impact of pairing two incompatible user signals in each frame. Unfortunately, blind scheduling results in system performance degradation, which means less system throughput or capacity.